Dietary total antioxidant capacity and colorectal cancer: A large case-control study in Italy

Plasma antioxidant potential measured by total radical trapping antioxidant parameter in a cohort of multiple sclerosis patients

BACKGROUND

Oxidative injury has been implicated as a mediator of demyelination, axonal damage, and neurodegeneration in multiple sclerosis (MS). There is a high demand for oxidative injury biomarkers. The aim of the study was to evaluate MS patients' plasma antioxidant potential using the total radical trapping parameter (TRAP) assay and examine its usefulness as an MS disease biomarker.

METHODS

A total number of 112 MS patients underwent an analysis of TRAP. In addition, plasma uric acid (UA) levels were analyzed. The neurological and radiological data were collected from patient records from Helsinki University Hospital during 2012-2013 when first-line injectables of moderate-efficacy, natalizumab (NTZ), and fingolimod (FTY) of high efficacy disease modifying therapies and in some cases azathioprine (AZT) were used to treat MS.

RESULTS

TRAP values were negatively associated with expanded disability status scale (EDSS) score with p-value .052, β = -28. There was also a negative association in TRAP values between patients with no medication (n = 22, TRAP mean 1255 μmol/L (95% confidence interval [CI] 1136-1374)) and patients who received NTZ, p-value .020 (n = 19, TRAP mean was 991 μmol/L (95% CI 849-1133) or FTY treatment, p-value .030 (n = 5, TRAP mean 982 μmol/L (95% CI 55-1909). Due to a small sample size, these results were not significant after applying a false discovery rate correction at a 0.05 significance level but are worth highlighting. Men in the study had higher TRAP values, p-value = .001 (TRAP mean 1320 ± 293 μmol/L) than women (TRAP mean 1082 ± 288 μmol/L). UA was positively associated with TRAP values, p-value <.001 and UA levels in men (UA mean 334.5 ± 62.6 μmol/L) were higher compared to women (UA mean 240 ± 55.8 μmol/L), t-test p-value <.001. The significant difference in TRAP levels between genders, with men showing higher TRAP values than women, may be attributed to the variation in UA levels.

CONCLUSION

Our findings suggest that lower plasma antioxidant potential is linked to more severe disability measured by EDSS scores. Patients treated with NTZ and FTY had reduced antioxidant power, which might be influenced by the active MS disease rather than the treatments themselves. The study reveals a strong positive correlation between UA levels and TRAP, particularly among women. However, men on average had better antioxidant potential than women. Neither the disease type nor the duration influences TRAP levels. While serving as a marker of antioxidant potential, plasma TRAP in MS patients does not reliably reflect overall oxidative stress (OS) and should not be solely used as an indicator of OS.

Dietary total antioxidant capacity and the risk of developing asthenozoospermia: a hospital-based case-control study in China

STUDY QUESTION

Is dietary total antioxidant capacity (DTAC) associated with the odds of developing asthenozoospermia in Chinese men?

SUMMARY ANSWER

There is no statistically significant association between DTAC indices and the odds of developing asthenozoospermia.

WHAT IS KNOWN ALREADY

Both diet and oxidative stress may be related to sperm quality; however, few studies have investigated the association between DTAC and sperm quality.

STUDY DESIGN, SIZE, DURATION

This case-control study was conducted from June 2020 to December 2020. Those diagnosed with asthenozoospermia were assigned to the case group, whereas those with normal sperm parameters were assigned to the control group. Data from a total of 553 cases and 586 controls were included in the final analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Men who had been referred to the infertility clinic of Shengjing Hospital of China Medical University were enrolled. Dietary intake was assessed using a validated food frequency questionnaire. DTAC was based on ferric-reducing ability of plasma (FRAP), total oxygen radical absorbance capacity (T-ORAC), hydrophilic oxygen radical absorbance capacity (H-ORAC), lipophilic oxygen radical absorbance capacity (L-ORAC), total phenolics (TP), total radical-trapping antioxidant parameter (TRAP), and Trolox equivalent antioxidant capacity (TEAC). Asthenozoospermia was defined according to the criteria published in the fifth edition of the World Health Organization laboratory manual for the examination and processing of human semen.

MAIN RESULTS AND THE ROLE OF CHANCE

No significant association was observed between the DTAC indices and the odds of asthenozoospermia after multivariable adjustment (T3 vs T1, odds ratio (OR) = 0.99, 95% CI: 0.73-1.33 for FRAP; OR = 1.05, 95% CI: 0.77-1.42 for T-ORAC; OR = 0.88, 95% CI: 0.65-1.18 for H-ORAC; OR = 0.98, 95% CI: 0.71-1.34 for L-ORAC; OR = 1.03, 95% CI: 0.76-1.39 for TP; OR = 1.18, 95% CI: 0.87-1.59 for TRAP; and OR = 1.15, 95% CI: 0.85-1.55 for TEAC). Both additive and multiplicative interaction analyses suggested that smoking might modify the association of T-ORAC with the odds of developing asthenozoospermia (relative excess risk due to interaction = 0.45, 95% CI: 0.07-0.83, attributable proportion due to interaction = 0.46, 95% CI: 0.07-0.84 for additive interaction; P = 0.033 for multiplicative interaction).

LIMITATIONS, REASONS FOR CAUTION

Recall bias and protopathic bias were inevitable in this retrospective case-control study. The estimation accuracy of the DTAC indices may have also affected the findings.

WIDER IMPLICATIONS OF THE FINDINGS

To the best of our knowledge, this is the first study to specifically investigate whether an association exists between DTAC and the odds of developing asthenozoospermia. Although no significant association was found, this study provides novel information pertaining to the fields of nutrition and human reproduction.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the JieBangGuaShuai Project of Liaoning Province (2021JH1/10400050), the Shengjing Hospital Clinical Research Project (M0071), and the Outstanding Scientific Fund of Shengjing Hospital (M1150). All authors have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

The association between dietary total antioxidant capacity and odds and severity of irritable bowel syndrome among Iranian adults: a cross-sectional study

Background

Little evidence is available in terms of the role of dietary antioxidants in the management of irritable bowel syndrome (IBS) disease. This study aimed to examine the association between dietary total antioxidant capacity (dTAC) and odds of IBS and its severity.

Methods

This cross-sectional study was conducted on 3,362 Iranian adults who were referred to health centers in Isfahan province, Iran. Participants' dietary intakes were collected using a semi-quantitative validated food frequency questionnaire (DS-FFQ). The dTAC was measured by the ferric-reducing antioxidant power (FRAP) method. Multivariable binary or ordinal logistic regression analyses were performed to estimate any associations between dTAC and odds of IBS, IBS severity, and IBS subtypes.

Results

The average age and BMI of the participants and dTAC score were 36.3 ± 7.87 year, 24.9 ± 3.82 kg/m2. The prevalence of IBS, IBS with constipation (IBS-C), IBS with diarrhoea (IBS-D), mixed IBS (IBS-M), and un-subtyped IBS (IBS-U) were 22.2, 7.5, 4.6, 3.8, and 6.2%, respectively. In crude and adjusted models, the results did not show any significant association between dTAC and odds of IBS among whole and gender-age stratified populations. Being in the third compared with the first tertile of dTAC was not also significantly associated with odds of IBS severity. Besides, there were no significant associations between dTAC and odds of IBS-C, IBS-D, IBS-M, and IBS-U.

Conclusion

This study indicates that dTAC may not be associated with the odds of IBS and its severity even after stratification for gender and body mass index.

Evaluation of The Antioxidant Capacity of Food Products: Methods, Applications and Limitations

Assays of total antioxidant capacity (TAC) are popular in the analysis of food products. This review presents the most popular assays of TAC and their limitations, databases of TAC of food products, their application in clinical studies, and the effect of processing on the TAC of food. The importance of sample preparation for TAC assays and striking effects of digestion in the gastrointestinal tract on the TAC of food are discussed. Critical opinions on the validity of food TAC assays are considered. It is concluded that TAC methods can be useful as screening assays for food quality control and as low-cost, high-throughput tools used to discover potential antioxidant sources and follow changes in the content of antioxidants during food processing. However, effects revealed by TAC assays should be followed and explained using more specific methods.

Association Between Dietary Total Antioxidant Capacity and Diet Quality in Adults

Background

Diet quality is a major contributor to human health. In addition, antioxidants have a great contribution to several chronic conditions. The purpose of this study was to evaluate if dietary total antioxidant capacity (TAC) can be considered as a measure of diet quality in a Middle Eastern country.

Methods

In this cross-sectional study on 6,724 Iranian adults, we used a validated food frequency questionnaire (FFQ) to assess dietary intakes. Data derived from the FFQ was used to calculate dietary TAC and well-known diet quality scores including alternate healthy eating index (AHEI) and dietary diversity score (DDS). Dietary TAC was calculated based on the ferric reducing-antioxidant power (FRAP) values reported in earlier publications. AHEI and DDS have also been constructed based on previous publications. Cross-classification was used to examine the agreement between these measures.

Results

Mean age and BMI of study participants were 36.89 ± 8.08 y and 24.97 ± 3.87 kg/m², respectively. We found that individuals in the highest tertile of dietary TAC had higher scores of AHEI (57.53 ± 0.20 vs. 52.03 ± 0.20, P < 0.001) and DDS (5.56 ± 0.03 vs. 4.15 ± 0.03, P < 0.001) compared with those in the lowest tertile. Participants' distribution on the basis of the cross-classification analysis indicated that the classifications were in exact agreement for 42.6%, within an adjacent tertile for 33.05%, and in gross misclassification for 20% of individuals. When this was examined between dietary TAC and DDS, we found that exact agreement in the classifications was for 59.2% of participants. Notably, a very low proportion of gross misclassification was seen in this regard such that only 6% of participants were classified in the opposing tertiles, indicating additional support for a good agreement.

Conclusion

We found that dietary TAC might be considered as a proper measure for the assessment of diet quality because it was well correlated with well-known measures of diet quality including DDS and AHEI scores.

Oxidative reactivity across kingdoms in the gut: Host immunity, stressed microbiota and oxidized foods

Reactive oxygen species play a major role in the induction of programmed cell death and numerous diseases. Production of reactive oxygen species is ubiquitous in biological systems such as humans, bacteria, fungi/yeasts, and plants. Although reactive oxygen species are known to cause diseases, little is known about the importance of the combined oxidative stress burden in the gut. Understanding the dynamics and the level of oxidative stress 'reactivity' across kingdoms could help ascertain the combined consequences of free radical accumulation in the gut lumen. Here, we present fundamental similarities of oxidative stress derived from the host immune cells, bacteria, yeasts, plants, and the therein-derived diets, which often accentuate the burden of free radicals by accumulation during storage and cooking conditions. Given the described similarities, oxidative stress could be better understood and minimized by monitoring the levels of oxidative stress in the feces to identify pro-inflammatory factors. However, we illustrate that dietary studies rarely monitor oxidative stress markers in the feces, and therefore our knowledge on fecal oxidative stress monitoring is limited. A more holistic approach to understanding oxidative stress 'reactivity' in the gut could help improve strategies to use diet and microbiota to prevent intestinal diseases.

Oxidative stress parameters as biomarkers of bladder cancer development and progression

The epidemiological studies confirm that the overproduction of free radical is an important factor of cancer induction as well as development, and loss of antioxidant systems efficiency is associated with an increased risk of carcinogenesis. While bladder cancer is the fourth most common type of cancer all over the world, there is little evidence of the advancing changes in oxidative/nitrative stress during the progression of bladder cancer. Our study aimed to investigate the plasma levels of typical markers of oxidative/nitrative stress depending on the clinical classification of bladder cancer differentiation and infiltration degree. We examined 40 patients with newly diagnosed bladder cancer and 20 healthy volunteers as a control group. We analysed the plasma levels of protein carbonyls, thiol groups, 3-nitrotyrosine, lipid peroxidation, as well as non-enzymatic plasma antioxidant capacity using DPPH^· and ABTS^·+ radicals. We confirmed that all analysed biomarkers are higher in enrolled BC patients than in healthy subjects. Furthermore, our findings demonstrate a positive correlation between the degree of bladder cancer progression and the level of oxidative stress, but no correlation in the case of NT-3. Based on obtained results, we might conclude that during carcinogenesis of the bladder increased oxidative damage of biomolecules is manifested. This indicates the participation of oxidative stress in the development of bladder cancer, and it is important the ensure the proper antioxidant protection.

Biomolecules Responsible for the Total Antioxidant Capacity (TAC) of Human Plasma in Healthy and Cardiopathic Individuals: A Chemical Speciation Model

(1) Background: Much effort has been expended to investigate the antioxidant capacity of human plasma, attempting to clarify the roles of both metabolic and food substances in determining defenses against oxidative stress. The relationship between the total antioxidant capacity (TAC) and the concentrations of redox-active biomolecules in the human plasma of healthy and cardiopathic individuals was investigated in the present study to develop a chemical speciation model. (2) Methods: Plasma was collected from 85 blood donors and from 25 cardiovascular surgery patients. The TAC was measured using the CUPRAC-BCS (CUPric Reducing Antioxidant Capacity — Bathocuproinedisulfonic acid) method. Biomolecule concentrations were determined via visible spectrophotometry or HPLC/RP techniques. The relationship between the TAC and the concentrations was defined by applying a multiple regression analysis. The significance of the variables was first tested, and chemical models were proposed for the two datasets. The model equation is TAC=∑iβi·Ai, where β_i and [A_i] are the electronic exchange and the molar concentrations of the i^th antioxidant component, respectively. (3) Results: The major contributions to the TAC, ~80%, come from endogenous compounds in both healthy and cardiopathic individuals, whereas the contributions from exogenous compounds were different between the two datasets. In particular, γ-tocopherol showed a different role in the chemical models developed for the two groups.

Dysmetabolisms Can Affect Total Antioxidant Capacity (TAC) of Human Plasma: Determination of Reference Intervals of TAC by Way of CUPRAC-BCS Method

The total antioxidant capacity (TAC) of human plasma is an index of the redox buffer capacity of this biological fluid and could be a biomarker for those disorders affecting redox status. Distinguishing physiological from pathological conditions needs a reference. Therefore, this work aims to define the reference intervals for TAC of human plasma of apparently healthy adult individuals. TAC was measured using the CUPRAC-BCS (CUPric reducing antioxidant capacity-bathocuproinedisulfonic acid) method previously optimized and tested in a clinical laboratory. A population of 500 blood donors was selected, plus an additional 222 pathological patients carrying specific defective metabolisms, namely, hyperuricemia, hyperbilirubinemia, and type 2 diabetic mellitus. The reference intervals of TAC were calculated according to international guidelines. Due to the response of a partitioning test, the reference intervals for healthy population were separately defined for male (258) and female (151) groups. The reference intervals (µmol L-1) resulted: 727-1248 for the male subgroup and 637-1048 for the female subgroup. The absence of an age effect on TAC values was verified. The reference intervals evaluated allow a discussion on some pathological conditions overloading the plasma with redox-active waste substances.

Twenty-five years of total antioxidant capacity measurement of foods and biological fluids: merits and limitations

This review summarises 25 years of investigations on antioxidants research in foods and biological fluids and critically analyses the merits and limitations of using the total antioxidant capacity (TAC) measurement in the metabolomic era. An enormous bulk of knowledge was produced regarding the antioxidant capacity of foods and large TAC databases were developed. A direct link between a food TAC value and any health benefit is erroneous and has led to several cases of consumer deception. However, the striking epidemiological evidence associating a high dietary TAC with some disease prevention and the availability of well-constructed TAC databases deserve attention and must be taken into account to establish the usefulness of measuring TAC in both foods and biological samples. The in vivo TAC measurement, usually performed in plasma, is influenced by many external factors, such as dietary habits, as well as environmental and behavioural factors, which are integrated towards homeostatic control by fine physiological mechanisms with high inter-individual variability. Therefore, plasma TAC cannot be considered as a unique biomarker of individual antioxidant status. However, the combined evaluation of plasma TAC with known markers of disease, individual metabolism, inflammation and genetics, as well as with markers of gut microbiota composition and activity, may lead to the identification of populations that are more responsive to food/diet TAC. In this framework, the appropriate use of TAC measurement both in food and in vivo can still provide support for the interpretation of complex phenomena and be a tool for sample screening when making a quick decision toward in-depth research investigations. © 2018 Society of Chemical Industry.

Dietary Total Antioxidant Capacity and Gestational Diabetes Mellitus: A Case-Control Study

Background

Elevated oxidative stress status has been reported among pregnant women with gestational diabetes mellitus (GDM). In diabetic condition, glucose and lipid peroxidation, and alteration in antioxidant defense lead to increased free radicals. The objective of this study was to investigate the association between dietary total antioxidant capacity (DTAC) and GDM.

Methods

This hospital-based case-control study was conducted in 463 pregnant women (healthy, n = 263; GDM, n = 200). Anthropometric indices, blood pressure, and biochemical analyses were measured. Dietary intake was assessed by the average of three 24-hour dietary intake records. DTAC was calculated by three indices: ferric reducing ability of plasma (FRAP), total radical-trapping antioxidant parameter (TRAP), and Trolox equivalent antioxidant capacity (TEAC). Multivariable logistic regression was performed to examine the relationship between DTAC and GDM risk in crude and adjusted models.

Results

The mean age and BMI were 28.33 ± 6.23 years and 29.67 ± 4.73 kg/m², respectively. Total energy, protein, and selenium intakes were significantly higher in cases than controls (P < 0.05). Moreover, intakes of carbohydrate, vitamins C, B6, and A, manganese, fruits, fruit juices, vegetables, legumes, and FRAP were significantly lower in cases than controls (P < 0.05). The risk of gestational diabetes mellitus was 85% lower among those in the highest tertile of FRAP (OR: 0.15; 95% CI: 0.08-0.29). There was no significant association between the risk of GDM and TRAP (OR: 1.62; 95% CI: 0.94-2.79) as well as TEAC (OR: 1.56; 95% CI: 0.89-2.72).

Conclusion

Pregnant women who were in the highest tertile of FRAP were at lower risk of GDM. However, larger prospective studies are needed to confirm our findings.

Association between dietary total antioxidant capacity and breast cancer: a case-control study in a Middle Eastern country

OBJECTIVE

The aim of this study was to determine the relationship between dietary total antioxidant capacity (dTAC) and risk of breast cancer among Iranian women.

DESIGN

In this hospital-based case-control study, dietary intake of participants was collected using a 168-item validated FFQ. Dietary TAC was assessed using FRAP assay considering. Logistic regression was used to obtain ORs for breast cancer across quartiles of dTAC.

SETTING

Cancer Institute, Iran.

PARTICIPANTS

We included 412 women with pathologically confirmed breast cancer and 456 apparently healthy controls.

RESULTS

Mean dTAC was 11·3 ± 5·8 for cases and 12·1 ± 7·9 for controls. A trend towards significant inverse association was seen between dTAC and odds of breast cancer in the whole population; such that after controlling for several potential confounders, individuals in the highest quartile of dTAC were 0·39 times less likely to have breast cancer than those in the lowest quartile (0·61; 95 % CI: 0·38, 0·99, P < 0·05). In the stratified analysis by menopausal status, we found that postmenopausal women with the greatest dTAC had lower odds for breast cancer, compared with those with the lowest dTAC (0·47; 95 % CI: 0·24, 0·93, P < 0·05). This association strengthened after additional adjustment for BMI (0·28; 95 % CI: 0·11, 0·72, P < 0·05). No significant association was seen between dTAC and odds of breast cancer in premenopausal women.

CONCLUSIONS

We found that dietary TAC was inversely associated with risk of breast cancer, in particular among postmenopausal women. Prospective cohort studies are needed to confirm these findings.

Dietary total antioxidant capacity and colorectal cancer and colorectal adenomatous polyps: a case-control study

Colorectal cancer (CRC) is the third most common and the third most deadly cancer worldwide. In Iran, CRC is the third and fifth most common cancer in females and males, respectively. Chronic oxidative stress has been implicated in the development of CRC and its precursor, colorectal adenomatous polyps (CAP). While there were a few studies that suggested a favorable role of individuals antioxidants on the CRC risk, the total antioxidant capacity (TAC) of diet has been less investigated. Consequently, the aim of this study is to investigate the association of TAC with the odds of CRC and CAP. This is a case-control study. The participants were 130 cases with incident, histologically confirmed CRC, 134 cases with incident of CAP and 243 hospital-based controls. TAC has been assessed with dietary ferric-reducing antioxidant potential and oxygen radical absorbance capacity method based on collected dietary intake data through a reproducible and valid food frequency questionnaire. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association between the TAC and CRC and CAP odds were estimated by multiple logistic regression. After controlling for potential confounders, TAC was significantly associated with CRC and CAP odds. (ORQ3-Q1 for CRC = 0.25, 95% CI: 0.13-0.46, Ptrend = 0.001. ORQ3-Q1 for CAP = 0.48, 95% CI: 0.27-0.85, Ptrend = 0.01). The findings of this study suggested an inverse association between TAC and CRC and CAP risk.

Comparative Assessment of Phenolic Profiles, Cellular Antioxidant and Antiproliferative Activities in Ten Varieties of Sweet Potato (Ipomoea Batatas) Storage Roots

Sweet potato is the sixth most important crop widely cultivated around the world with abundant varieties. Different varieties gain different phenolic profiles which has drawn researchers' attention for its unique health benefits. Our study evaluated the phenolic profiles, total and cellular antioxidant activities, antiproliferative activities, and cytotoxicity in 10 cultivated varieties of sweet potato in different colours. Among fourteen metabolites detected in our study, hyperoside, ferulic acid and caffeic acid were considered as prominent in SPSRs. According to the principle component analysis, phytochemical composition of HX22, YS15 and YS7 was quite similar. The results also evidenced that purple-fleshed varieties, such as YS43, YZ7 and YY153, have higher total phenolics content and corresponding stronger total antioxidant capacities as well as cellular antiproliferative activities against human liver cancer HepG2 cells than other varieties. The extremely significant correlation between phenolics and total antioxidant activity was also revealed by Pearson correlation analysis (p < 0.05). However, no significant relevance was found between intracellular antioxidant activity and total phenolic content or flesh colour of sweet potatoes.

Diet, Microbiota, and Colorectal Cancer

The intestinal epithelium is a very dynamic tissue under a high regenerative pressure, which makes it susceptible to malignant transformation. Proper integration of various cell signaling pathways and a balanced cross talk between different cell types composing the organ are required to maintain intestinal homeostasis. Dysregulation of this balance can lead to colorectal cancer (CRC). Here, we review important insights into molecular and cellular mechanisms of CRC. We discuss how perturbation in complex regulatory networks, including the Wnt, Notch, BMP, and Hedgehog pathways; and how variations in inflammatory signaling, nutrients, and microbiota can affect intestinal homeostasis contributing to the malignant transformation of intestinal cells.

Organochlorine and organophosphorous pesticides may induce colorectal cancer; A case-control study

OBJECTIVES

Among the numerous agents, genetic factors and environmental elements such as pesticides have an important role in colorectal cancer (CRC) incidence. The present study aimed to investigate the probable-role of some organochlorine pesticides (OCPs) and organophosphorous pesticides (OPPs) in patients with CRC.

METHODS

In this case-control study, 42 patients with CRC and 30 healthy subjects were selected. The serum levels of some OCPs (α-HCH, β-HCH, γ-HCH, 2,4 DDE, 4,4 DDE, 2,4DDT and 4,4DDT) were measured by gas chromatography (GC) method. Serum levels of malondialdehyde (MDA), and total antioxidant capacity (TAC) as well as the enzyme activity of acetylcholinesterase (AChE) and arylesterase activity of Paraoxonase-1 (PON-1) were evaluated in all participants. The methylation specific PCR (MSP) assay was used for determining the methylation status of CpG island of p16 and MGMT genes in CRC patients.

RESULTS

The mean serum levels of each OCPs were significantly higher in the patient group compared to the control group (P < 0.001). The AChE and arylesterase activity of PON-1 in the patient group were significantly lower than the control group (P < 0.001). The mean serum levels of MDA and TAC in the serum of the patient group were significantly higher than the control group (P < 0.001 and P < 0.002, respectively). The current findings demonstrated significantly hypermethylation of p16 promoter in CRC patients.

CONCLUSION

Regarding the higher levels of OCPs in CRC patients, along with hypermethylation of the p16 promoter gene, diminishing in AChE and PON-1 activity and increasing in oxidative stress factors, the role of OCPs and OPPs in the CRC progression in the South-East of Iran may be assumed.

Dietary pattern, dietary total antioxidant capacity, and dyslipidemia in Korean adults

Background

Abnormal diet is considered to be an important risk factor for dyslipidemia. However, so far, most studies have focused on the association between single factors only, such as specific nutrients, foods, or dietary patterns, and dyslipidemia risk. This study aimed to examine the association of the joint interaction between dietary pattern and dietary total antioxidant capacity (TAC) with dyslipidemia.

Methods

We performed a dietary pattern analysis and calculated the dietary TAC based on 24-h dietary recall (DR) data from Korea National Health and Nutrition Examination Survey (KNHANES) 2007–2012, which is representative population-based cross-sectional survey in Korea. A total of 29,624 participants aged over 19 years were included for the analysis. The number of people with hypercholesterolemia, hypertriglyceridemia, and hypoHDL-cholesterolemia was 3703, 3513, and 9802, respectively. We examined the association between the joint classifications of dietary pattern score tertiles and dietary TAC level tertiles and dyslipidemia.

Results

Our results demonstrated that the “Rice & Kimchi” pattern was associated with low prevalence of hypercholesterolemia, and high prevalence of hypertriglyceridemia and hypoHDL-cholesterolemia; whereas the pattern of both “Oil, sweets, fish & other vegetables” and “Grain, bean, nuts, vegetables & fruits” were associated with low prevalence of hypertriglyceridemia. Also we demonstrated that for all dietary patterns except for the “Grain, bean, nuts, vegetables & fruits”, dietary TAC was inversely associated with hypertriglyceridemia.

Conclusion

This study provides basic data for the lipid-lowering effect of dietary TAC and its interaction with dietary patterns. Further study will be needed to investigate the association between dietary TAC and dietary patterns with other diseases like metabolic syndrome, cardiovascular disease, or cancer.

Electronic supplementary material

The online version of this article (10.1186/s12937-019-0459-x) contains supplementary material, which is available to authorized users.

Dietary Inflammatory Index, Dietary Non-Enzymatic Antioxidant Capacity, and Colorectal and Breast Cancer Risk (MCC-Spain Study)

Inflammation and antioxidant capacity have been associated with colorectal and breast cancer. We computed the dietary inflammatory index (DII^®), and the total dietary non-enzymatic antioxidant capacity (NEAC) and associated them with colorectal and breast cancer risk in the population-based multi case-control study in Spain (MCC-Spain). We included 1852 colorectal cancer and 1567 breast cancer cases, and 3447 and 1486 population controls, respectively. DII score and NEAC were derived using data from a semi-quantitative validated food frequency questionnaire. Unconditional logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (95%CI) for energy-adjusted DII (E-DII), and a score combining E-DII and NEAC. E-DII was associated with colorectal cancer risk (OR = 1.93, highest quartile versus lowest, 95%CI:1.60–2.32; p-trend: <0.001); this increase was observed for both colon and rectal cancer. Less pronounced increased risks were observed for breast cancer (OR = 1.22, highest quartile versus lowest, 95%CI:0.99–1.52, p-trend: >0.10). The combined score of high E-DII scores and low antioxidant values were associated with colorectal cancer risk (OR = 1.48, highest quartile versus lowest, 95%CI: 1.26–1.74; p-trend: <0.001), but not breast cancer. This study provides evidence that a pro-inflammatory diet is associated with increased colorectal cancer risk while findings for breast cancer were less consistent.

Luteolin promotes apoptotic cell death via upregulation of Nrf2 expression by DNA demethylase and the interaction of Nrf2 with p53 in human colon cancer cells

Luteolin, a dietary flavone, modulates various signaling pathways involved in carcinogenesis. In this study, we investigated the molecular mechanism that underlies the apoptotic effects of luteolin mediated by DNA demethylation of the nuclear factor erythroid 2-related factor 2 (Nrf2) promoter and the interaction of Nrf2 and p53, a tumor suppressor, in human colon cancer cells. Luteolin increased the expression of apoptosis-related proteins and antioxidant enzymes. In DNA methylation, luteolin inhibited the expression of DNA methyltransferases, a transcription repressor, and increased the expression and activity of ten-eleven translocation (TET) DNA demethylases, a transcription activator. Methyl-specific polymerase chain reaction and bisulfite genomic sequencing indicated that luteolin decreased the methylation of the Nrf2 promoter region, which corresponded to the increased mRNA expression of Nrf2. In addition, luteolin increased TET1 binding to the Nrf2 promoter, as determined using a chromatin immunoprecipitation (ChIP) assay. TET1 knockdown decreased the percentages of luteolin-treated cells in sub-G₁ phase and cells with fragmented nuclei. Furthermore, complex formation between p53 and Nrf2 was involved in the apoptotic effects of luteolin. These results provide insight into the mechanism that underlies the anticancer effects of luteolin on colon cancer, which involve the upregulation of Nrf2 and its interaction with the tumor suppressor.

A molecule found in fruits, vegetables and herbs helps kill colon cancer cells by activating a master regulator of detoxifying enzymes. Jin Won Hyun from Jeju National University School of Medicine in South Korea and colleagues treated human colon cancer cells with luteolin, a molecule that occurs naturally in many food plants. They showed that luteolin increased the levels of proteins involved in cell death and antioxidant responses by causing DNA-modifying enzymes to strip suppressive chemical markers off the gene encoding Nrf2, a protein that regulates antioxidant effects. Nrf2 levels subsequently increased and the protein interacted with the tumor suppressor p53 to facilitate destruction of the colon cancer cells. The findings offer a mechanistic basis for using luteolin to help prevent and treat cancer.

Genetic variant predictors of gene expression provide new insight into risk of colorectal cancer

Genome-wide association studies have reported 56 independently associated colorectal cancer (CRC) risk variants, most of which are non-coding and believed to exert their effects by modulating gene expression. The computational method PrediXcan uses cis-regulatory variant predictors to impute expression and perform gene-level association tests in GWAS without directly measured transcriptomes. In this study, we used reference datasets from colon (n = 169) and whole blood (n = 922) transcriptomes to test CRC association with genetically determined expression levels in a genome-wide analysis of 12,186 cases and 14,718 controls. Three novel associations were discovered from colon transverse models at FDR ≤ 0.2 and further evaluated in an independent replication including 32,825 cases and 39,933 controls. After adjusting for multiple comparisons, we found statistically significant associations using colon transcriptome models with TRIM4 (discovery P = 2.2 × 10- 4, replication P = 0.01), and PYGL (discovery P = 2.3 × 10- 4, replication P = 6.7 × 10- 4). Interestingly, both genes encode proteins that influence redox homeostasis and are related to cellular metabolic reprogramming in tumors, implicating a novel CRC pathway linked to cell growth and proliferation. Defining CRC risk regions as one megabase up- and downstream of one of the 56 independent risk variants, we defined 44 non-overlapping CRC-risk regions. Among these risk regions, we identified genes associated with CRC (P < 0.05) in 34/44 CRC-risk regions. Importantly, CRC association was found for two genes in the previously reported 2q25 locus, CXCR1 and CXCR2, which are potential cancer therapeutic targets. These findings provide strong candidate genes to prioritize for subsequent laboratory follow-up of GWAS loci. This study is the first to implement PrediXcan in a large colorectal cancer study and findings highlight the utility of integrating transcriptome data in GWAS for discovery of, and biological insight into, risk loci.

Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies

The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. A systematic search was performed in PubMed and Scopus, from their inception up to October 2017. Prospective observational studies reporting risk estimates of all-cause mortality in relation to dietary intake and/or circulating concentrations of antioxidants were included. Random-effects meta-analyses were conducted. Forty-one prospective observational studies (total n = 507,251) involving 73,965 cases of all-cause mortality were included. The RRs of all-cause mortality for the highest compared with the lowest category of circulating antioxidant concentrations were as follows: total carotenes, 0.60 (95% CI: 0.46, 0.74); vitamin C, 0.61 (95% CI: 0.53, 0.69); selenium, 0.62 (95% CI: 0.45, 0.79); β-carotene, 0.63 (95% CI: 0.57, 0.70); α-carotene, 0.68 (95% CI: 0.58, 0.78); total carotenoids, 0.68 (95% CI: 0.56, 0.80); lycopene, 0.75 (95% CI: 0.54, 0.97); and α-tocopherol, 0.84 (95% CI: 0.77, 0.91). The RRs for dietary intakes were: total carotenoids, 0.76 (95% CI: 0.66, 0.85); total antioxidant capacity, 0.77 (95% CI: 0.73, 0.81); selenium, 0.79 (95% CI: 0.73, 0.85); α-carotene, 0.79 (95% CI: 0.63, 0.94); β-carotene, 0.82 (95% CI: 0.77, 0.86); vitamin C, 0.88 (95% CI: 0.83, 0.94); and total carotenes, 0.89 (95% CI: 0.81, 0.97). A nonsignificant inverse association was found for dietary zinc, zeaxanthin, lutein, and vitamin E. The nonlinear dose-response meta-analyses demonstrated a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C, and total carotenoids. The association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C. The present study indicates that adherence to a diet with high antioxidant properties may reduce the risk of all-cause mortality. Our results confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.

Dietary Supplementation of Selenoneine-Containing Tuna Dark Muscle Extract Effectively Reduces Pathology of Experimental Colorectal Cancers in Mice

Selenoneine is an ergothioneine analog with greater antioxidant activity and is the major form of organic selenium in the blood, muscles, and other tissues of tuna. The aim of this study was to determine whether a selenoneine-rich diet exerts antioxidant activities that can prevent carcinogenesis in two types of colorectal cancer model in mice. We administrated selenoneine-containing tuna dark muscle extract (STDME) to mice for one week and used azoxymethane (AOM) and dextran sodium sulfate (DSS) for inducing colorectal carcinogenesis. Next, we examined the incidence of macroscopic polyps and performed functional analysis of immune cells from the spleen. In the AOM/DSS-induced colitis-associated cancer (CAC) model, the oral administration of STDME significantly decreased tumor incidence and inhibited the accumulation of myeloid-derived suppressor cells (MDSCs) while also inhibiting the downregulation of interferon-γ (IFN-γ) production during carcinogenesis. These results suggest that dietary STDME may be an effective agent for reducing colorectal tumor progression.

The dietary flavone luteolin epigenetically activates the Nrf2 pathway and blocks cell transformation in human colorectal cancer HCT116 cells

Colorectal cancer remains a leading malignancy in humans. The importance of epigenetic modification in the development of this disease is now being recognized. The reversible and dynamic nature of epigenetic modifications provides a promising strategy in colorectal cancer chemoprevention and treatment. Luteolin (LUT), a flavone dietary phytochemical, can modulate various signaling pathways involved in carcinogenesis. Many studies have demonstrated that LUT inhibits colorectal carcinogenesis by activating the Nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant-responsive element (ARE) pathway. However, the potential epigenetic mechanism underlying Nrf2/ARE pathway activation remains unclear. In this study, we aimed to explore the anticancer potential of LUT in human colon cancer cells and the epigenetic regulation of the Nrf2/ARE pathway. Specifically, our data showed that LUT suppressed cell proliferation and cellular transformation of HCT116 and HT29 cells in a dose-dependent manner. Additionally, quantitative real-time polymerase chain reaction and Western blot analysis were performed to determine the mRNA and protein expression of Nrf2 and its downstream genes after LUT treatment. Bisulfite genomic sequencing revealed that methylation of the Nrf2 promoter region was decreased by LUT, corresponding with the increased mRNA expression of Nrf2. Decreased protein levels and enzyme activities of epigenetic modifying enzymes, such as DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), were also observed in LUT-treated HCT116 cells. In summary, our findings suggest that LUT may exert its antitumor activity in part via epigenetic modifications of the Nrf2 gene with subsequent induction of its downstream antioxidative stress pathway.

Association study of dietary non-enzymatic antioxidant capacity (NEAC) and colorectal cancer risk in the Spanish Multicase-Control Cancer (MCC-Spain) study

PURPOSE

Studies attempting to link dietary non-enzymatic antioxidant activity (NEAC) and colorectal cancer (CRC) risk have reported mixed results. We examined this association in the Spanish Multicase-Control Study considering the likely influence of coffee and other dietary factors.

METHODS

1718 CRC cases and 3312 matched-controls provided information about diet through a validated 140-item food frequency questionnaire. Dietary NEAC was estimated for three methods [total radical-trapping antioxidant parameters (TRAP), ferric reducing/antioxidant power (FRAP) and TEAC-ABTS] using published values of NEAC content in food, with and without coffee's NEAC. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated through unconditional logistic regression models adjusted for lifestyle and dietary factors.

RESULTS

Overall dietary intake of NEAC was significantly lower in cases compared to controls and associated with a significantly reduced CRC risk, in both men (OR_Q5vsQ1 = 0.67, 95% CI 0.47-0.96 for FRAP) and women (OR_Q5vsQ1 = 0.53, 95% CI 0.32-085 for FRAP), in multivariate models with and without the antioxidant contribution from coffee. The effect was similar for all the NEAC methods evaluated and for both colon and rectum. The association between dietary NEAC and CRC risk became non-significant when adjusting for fiber intake. However, intakes of NEAC and fiber were correlated.

CONCLUSION

This study indicates that intake of an antioxidant-rich plant-based diet, both with and without NEAC from coffee, is associated with decreased CRC risk.

Increased colon cancer risk after severe Salmonella infection

BACKGROUND

Colon cancer constitutes one of the most frequent malignancies. Previous studies showed that Salmonella manipulates host cell signaling pathways and that Salmonella Typhimurium infection facilitates colon cancer development in genetically predisposed mice. This epidemiological study examined whether severe Salmonella infection, usually acquired from contaminated food, is associated with increased colon cancer risk in humans.

METHODS AND FINDINGS

We performed a nationwide registry-based study to assess colon cancer risk after diagnosed Salmonella infection. National infectious disease surveillance records (1999-2015) for Dutch residents aged ≥20 years when diagnosed with salmonellosis (n = 14,264) were linked to the Netherlands Cancer Registry. Salmonella-infected patients were laboratory-confirmed under medical consultation after 1-2 weeks of illness. These datasets also contained information on Salmonella serovar and type of infection. Colon cancer risk (overall and per colon subsite) among patients with a diagnosed Salmonella infection was compared with expected colon cancer risk in the general population. Data from the nationwide registry of histo- and cytopathology (PALGA) and Statistics Netherlands (CBS) allowed assessing potential effects of age, gender, latency, socioeconomic status, genetic predisposition, inflammatory bowel disease (IBD), and tumor features. We found that compared to the general population, colon cancer risk was significantly increased (standardized incidence ratio [SIR] 1.54; 95%CI 1.09-2.10) among patients with Salmonella infection diagnosed <60 years of age. Such increased risk concerned specifically the ascending/transverse colon (SIR 2.12; 95%CI 1.38-3.09) after S. Enteritidis infection (SIR 2.97; 95%CI 1.73-4.76). Salmonellosis occurred more frequently among colon cancer patients with pre-infectious IBD, a known risk factor for colon cancer. Colon tumors of patients with a history of Salmonella infection were mostly of low grade.

CONCLUSIONS

Patients diagnosed with severe salmonellosis have an increased risk of developing cancer in the ascending/transverse parts of the colon. This risk concerns particularly S. Enteritidis infection, suggesting a contribution of this major foodborne pathogen to colon cancer development.

The Interaction between Dietary Fiber and Fat and Risk of Colorectal Cancer in the Women's Health Initiative

Combined intakes of specific dietary fiber and fat subtypes protect against colon cancer in animal models. We evaluated associations between self-reported individual and combinations of fiber (insoluble, soluble, and pectins, specifically) and fat (omega-6, omega-3, and docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), specifically) and colorectal cancer (CRC) risk in the Women's Health Initiative prospective cohort (n = 134,017). During a mean 11.7 years (1993-2010), 1952 incident CRC cases were identified. Cox regression models computed multivariate adjusted hazard ratios to estimate the association between dietary factors and CRC risk. Assessing fiber and fat individually, there was a modest trend for lower CRC risk with increasing intakes of total and insoluble fiber (p-trend 0.09 and 0.08). An interaction (p = 0.01) was observed between soluble fiber and DHA + EPA, with protective effects of DHA + EPA with lower intakes of soluble fiber and an attenuation at higher intakes, however this association was no longer significant after correction for multiple testing. These results suggest a modest protective effect of higher fiber intake on CRC risk, but not in combination with dietary fat subtypes. Given the robust results in preclinical models and mixed results in observational studies, controlled dietary interventions with standardized intakes are needed to better understand the interaction of specific fat and fiber subtypes on colon biology and ultimately CRC susceptibility in humans.

Total antioxidant intake and prostate cancer in the Cancer of the Prostate in Sweden (CAPS) study. A case control study

Background

The total intake of dietary antioxidants may reduce prostate cancer risk but available data are sparse and the possible role of supplements unclear. We investigated the potential association between total and dietary antioxidant intake and prostate cancer in a Swedish population.

Methods

We used FFQ data from 1499 cases and 1112 controls in the population based case–control study Cancer of the Prostate in Sweden (CAPS). The ferric reducing antioxidant potential (FRAP) assay was used to assess the total antioxidant capacity (TAC) of diet and supplements. We calculated odds ratios (ORs) for the risk of prostate cancer across quintiles of antioxidant intake from all foods, from fruit and vegetables only, and from dietary supplements using unconditional logistic regression.

Results

Coffee comprised 62 % of the dietary antioxidant intake, tea 4 %, berries 4 %, chocolate 2 %, and boiled potatoes 2 %. In total 19 % and 13 % of the population took multivitamins and supplemental Vitamin C respectively, on a regular basis. Antioxidant intake from all foods and from fruits and vegetables separately measured by the FRAP assay was not associated with prostate cancer risk. For antioxidant intake from supplements we found a positive association with total, advanced, localized, high grade and low grade prostate cancer in those above median supplemental TAC intake of users compared to non-users (Adjusted ORs for total prostate cancer: 1.37, 95 % CI 1.08–1.73, advanced: 1.51, 95 % CI 1.11–2.06, localized: 1.36. 95 % CI 1.06–1.76, high grade 1.60, 95 % CI 1.06–2.40, low grade 1.36, 95 % CI 1.03–1.81). A high intake of coffee (≥6 cups/day) was associated with a possible risk reduction of fatal and significantly with reduced risk for high grade prostate cancer, adjusted OR: 0.45 (95 % CI: 0.22–0.90), whereas a high intake of chocolate was positively associated with risk of total, advanced, localized and low grade disease (adjusted OR for total: 1.43, 95 % CI 1.12–1.82, advanced: 1.40, 95 % CI 1.01–1.96, localized: 1.43, 95 % CI 1.08–1.88, low-grade: 1.41, 95 % CI 1.03–1.93).

Conclusions

Total antioxidant intake from diet was not associated with prostate cancer risk. Supplement use may be associated with greater risk of disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2486-8) contains supplementary material, which is available to authorized users.

Dietary total antioxidant capacity is associated with plasmatic antioxidant capacity, nutrient intake and lipid and DNA damage in healthy women

Dietary total antioxidant capacity (DTAC) seems to be associated with reducing risk of diseases. However, data about the influence of the DTAC on oxidative stress parameters are scarce. The aim of this study was to estimate the DTAC and its influence on plasma total antioxidant capacity (PTAC), and damage to lipids, proteins and DNA in healthy women. It was found a positive correlation between DTAC and PTAC in young and healthy subjects, where presumably the endogenous defenses are fully functional. DTAC and PTAC were positively correlated with the intake of known antioxidants, including vitamin C and polyphenols. The DTAC exhibited a negative correlation with lipid oxidative damage, while PTAC showed a negative correlation with DNA damage. This data contributes to better understanding of the recommended dietary antioxidant intake for promoting health.

Dietary antioxidant capacity and all-cause and cause-specific mortality in the E3N/EPIC cohort study

PURPOSE

The cellular oxidative stress (balance between pro-oxidant and antioxidant) may be a major risk factor for chronic diseases. Antioxidant capacity of human diet can be globally assessed through the dietary non-enzymatic antioxidant capacity (NEAC). Our aim was to investigate the relationship between the NEAC and all-cause and cause-specific mortality, and to test potential interactions with smoking status, a well-known pro-oxidant factor.

METHODS

Among the French women of the E3N prospective cohort study initiated in 1990, including 4619 deaths among 1,199,011 persons-years of follow-up. A validated dietary history questionnaire assessed usual food intake; NEAC intake was estimated using a food composition table from two different methods: ferric ion reducing antioxidant power (FRAP) and total radical-trapping antioxidant parameter (TRAP). Hazard ratio (HR) estimates and 95 % confidence intervals (CI) were derived from Cox proportional hazards regression models.

RESULTS

In multivariate analyses, FRAP dietary equivalent intake was inversely associated with mortality from all-causes (HR for the fourth vs. the first quartile: HR₄ = 0.75, 95 % CI 0.67, 0.83, p _trend < 0.0001), cancer, and cardiovascular diseases. Similar results were obtained with TRAP. There was an interaction between NEAC dietary equivalent intake and smoking status for all-cause and cardiovascular disease mortality, but not cancer mortality (respectively, for FRAP, p _inter = 0.002; 0.013; 0.113, results were similar with TRAP), and the association was the strongest among current smokers.

CONCLUSION

This prospective cohort study highlights the importance of antioxidant consumption for mortality prevention, especially among current smokers.

Heme Iron Intake, Dietary Antioxidant Capacity, and Risk of Colorectal Adenomas in a Large Cohort Study of French Women

BACKGROUND

Nitrosylated and non-nitrosylated heme iron from red processed and nonprocessed meat have been associated with increased colorectal carcinogenesis. Mechanisms include oxidative processes. It has been hypothesized that dietary antioxidants could counteract the effects of heme iron. We investigated the relationships between heme iron intake and the risk of colorectal adenomas, and a potential interaction with the dietary antioxidant capacity, in the E3N prospective cohort study.

METHODS

The study included 17,397 women, who underwent at least one colonoscopy. Among them, 1,409 were diagnosed with at least one first colorectal adenoma during the 103,253 person-years of follow-up. Dietary intake was measured by a semiquantitative food history questionnaire. HR estimates and 95% confidence intervals (CI) were obtained from Cox proportional hazards models, adjusted for potential confounders.

RESULTS

Heme iron intake was positively associated with colorectal and colon adenoma risks [HR for the fourth vs. first quartile: HR4 = 1.36 (1.13-1.65), Ptrend = 0.001 and HR4 = 1.49; 95% CI, 1.19-1.87; Ptrend = 0.0003, respectively]. Nonnitrosylated and nitrosylated heme iron intakes were, respectively, associated with advanced distal and proximal adenoma risks. There was a dose-effect relationship between the heme iron to total dietary antioxidant capacity ratio and colorectal adenoma risk.

CONCLUSION

In this prospective cohort study, the association between heme iron and colorectal adenoma risk was found to depend on site, nitrosylation or not, and the ratio with the NEAC.

IMPACT

These results emphasize the need for a global assessment of diet when considering nutritional prevention of colorectal carcinogenesis. Cancer Epidemiol Biomarkers Prev; 25(4); 640-7. ©2016 AACR.

Contribution of Macromolecular Antioxidants to Dietary Antioxidant Capacity: A Study in the Spanish Mediterranean Diet

Epidemiological and clinical studies show that diets with a high antioxidant capacity, such us those rich in plant food and beverages, are associated with significant decreases in the overall risk of cardiovascular disease or colorectal cancer. Current studies on dietary antioxidants and dietary antioxidant capacity focus exclusively on low molecular weight or soluble antioxidants (vitamins C and E, phenolic compounds and carotenoids), ignoring macromolecular antioxidants. These are polymeric phenolic compounds or polyphenols and carotenoids linked to plant food macromolecules that yield bioavailable metabolites by the action of the microbiota with significant effects either local and/or systemic after absorption. This study determined the antioxidant capacity of the Spanish Mediterranean diet including for the first time both soluble and macromolecular antioxidants. Antioxidant capacity and consumption data of the 54 most consumed plant foods and beverages were used. Results showed that macromolecular antioxidants are the major dietary antioxidants, contributing a 61% to the diet antioxidant capacity (8000 μmol Trolox, determined by ABTS method). The antioxidant capacity data for foods and beverages provided here may be used to estimate the dietary antioxidant capacity in different populations, where similar contributions of macromolecular antioxidants may be expected, and also to design antioxidant-rich diets. Including macromolecular antioxidants in mechanistic, intervention and observational studies on dietary antioxidants may contribute to a better understanding of the role of antioxidants in nutrition and health.

Dietary Total Antioxidant Capacity and Colorectal Cancer in the Italian EPIC Cohort

Background

Colorectal cancer is the third most common cancer worldwide. Diet has been hypothesized as involved in colorectal cancer etiology, but few studies on the influence of total dietary antioxidant intake on colorectal cancer risk have been performed.

Methods

We investigated the association between colorectal cancer risk and the total antioxidant capacity (TAC) of the diet, and also of intake of selected antioxidants, in 45,194 persons enrolled in 5 centers (Florence, Naples, Ragusa, Turin and Varese) of the European Prospective Investigation into Cancer and Nutrition (EPIC) Italy study. TAC was estimated by the Trolox equivalent antioxidant capacity (TEAC) assay. Hazard ratios (HRs) for developing colorectal cancer, and colon and rectal cancers separately, adjusted for confounders, were estimated for tertiles of TAC by Cox modeling, stratifying by center.

Results

Four hundred thirty-six colorectal cancers were diagnosed over a mean follow-up of 11.28 years. No significant association between dietary TAC and colorectal cancer incidence was found. However for the highest category of TAC compared to the lowest, risk of developing colon cancer was lower (HR: 0.63; 95% CI: 0.44–0.89, P trend: 0.008). By contrast, increasing TAC intake was associated with significantly increasing risks of rectal cancer (2nd tertile HR: 2.09; 95%CI: 1.19–3.66; 3rd tertile 2.48 95%CI: 1.32–4.66; P trend 0.007). Intakes of vitamin C, vitamin E, and ß-carotene were not significantly associated with colorectal cancer risk.

Conclusions

Further prospective studies are needed to confirm the contrasting effects of high total antioxidant intake on risk of colon and rectal cancers.

Fruit and vegetables and cancer risk: a review of southern European studies

High intakes of fruit and vegetables may reduce the risk of cancer at several sites. Evidence has been derived mainly from case-control studies. We reviewed the relationship between consumption of vegetables and fruit and the risk of several common cancers in a network of Italian and Swiss case-control studies including over 10,000 cases of fourteen different cancers and about 17,000 controls. Data were suggestive of a protective role of vegetable intake on the risk of several common epithelial cancers. OR for the highest compared with the lowest levels of consumption ranged from 0.2 (larynx, oral cavity and pharynx) to 0.9 (prostate). Inverse associations were found for both raw and cooked vegetables, although for upper digestive tract cancers the former were somewhat stronger. Similar inverse associations were found for cruciferous vegetables. Frequent consumption of allium vegetables was also associated with reduced risk of several cancers. Fruit was a favourable correlate of the risk of several cancers, particularly of the upper digestive tract, with associations generally weaker than those reported for vegetables. A reduced risk of cancers of the digestive tract and larynx was found for high consumption of citrus fruit. Suggestive protections against several forms of cancer, mainly digestive tract cancers, were found for high consumption of apples and tomatoes. High intakes of fibres, flavonoids and proanthocyanidins were inversely related to various forms of cancer. In conclusion, data from our series of case-control studies suggested a favourable role of high intakes of fruit and vegetables in the risk of many common cancers, particularly of the digestive tract. This adds evidence to the indication that aspects of the Mediterranean diet may have a favourable impact not only on CVD, but also on several common (epithelial) cancers, particularly of the digestive tract.

Vitamin E intake from natural sources and head and neck cancer risk: a pooled analysis in the International Head and Neck Cancer Epidemiology consortium

BACKGROUND

Evidence for the possible effect of vitamin E on head and neck cancers (HNCs) is limited.

METHODS

We used individual-level pooled data from 10 case-control studies (5959 cases and 12 248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium to assess the association between vitamin E intake from natural sources and cancer of the oral cavity/pharynx and larynx. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models applied to quintile categories of non-alcohol energy-adjusted vitamin E intake.

RESULTS

Intake of vitamin E was inversely related to oral/pharyngeal cancer (OR for the fifth vs the first quintile category=0.59, 95% CI: 0.49-0.71; P for trend <0.001) and to laryngeal cancer (OR=0.67, 95% CI: 0.54-0.83, P for trend <0.001). There was, however, appreciable heterogeneity of the estimated effect across studies for oral/pharyngeal cancer. Inverse associations were generally observed for the anatomical subsites of oral and pharyngeal cancer and within covariate strata for both sites.

CONCLUSION

Our findings suggest that greater vitamin E intake from foods may lower HNC risk, although we were not able to explain the heterogeneity observed across studies or rule out certain sources of bias.

Inflammatory potential of diet and risk of colorectal cancer: a case-control study from Italy

Diet and inflammation have been suggested to be important risk factors for colorectal cancer (CRC). In the present study, we examined the association between the dietary inflammatory index (DII) and the risk of CRC in a multi-centre case-control study conducted between 1992 and 1996 in Italy. The study included 1225 incident colon cancer cases, 728 incident rectal cancer cases and 4154 controls hospitalised for acute non-neoplastic diseases. The DII was computed based on dietary intake assessed using a validated seventy-eight-item FFQ that included assessment of alcohol intake. Logistic regression models were used to estimate the OR adjusted for age, sex, study centre, education, BMI, alcohol drinking, physical activity and family history of CRC. Energy intake was adjusted using the residual method. Subjects with higher DII scores (i.e. with a more pro-inflammatory diet) had a higher risk of CRC, with the DII being used both as a continuous variable (OR(continuous) 1.13, 95 % CI 1.09, 1.18) and as a categorical variable (OR(quintile 5 v. 1) 1.55, 95 % CI 1.29, 1.85; P for trend < 0.0001). Similar results were observed when the analyses were carried out separately for colon and rectal cancer cases. These results indicate that a pro-inflammatory diet is associated with an increased risk of CRC.

Non-enzymatic antioxidant capacity and risk of gastric cancer

BACKGROUND

Consumption of fruit and vegetables has been inversely related to gastric cancer. Two studies found that dietary antioxidant capacity has some role in explaining this association. We investigated the overall antioxidant effect from diet on gastric cancer using three measures of non-enzymatic antioxidant capacity (NEAC).

METHODS

We used data from an Italian case-control study including 230 patients with incident, histologically confirmed gastric cancer, and 547 frequency matched controls admitted to the same hospitals for acute non-neoplastic diseases. A reproducible and valid food frequency questionnaire was used to assess subjects' usual diet. NEAC was measured using Italian food composition tables in terms of Trolox equivalent antioxidant capacity (TEAC), Ferric reducing-antioxidant power (FRAP) and Total radical-trapping antioxidant parameter (TRAP). We estimated the odds ratios (OR) of gastric cancer and the corresponding 95% confidence intervals (CI) using conditional logistic regression models including terms for recognized gastric cancer risk factors and total energy intake.

RESULTS

NEAC was inversely related with gastric cancer risk with ORs for the highest versus the lowest quintile of 0.54 (95%CI, 0.33-0.88) for TEAC, 0.67 (95%CI, 0.42-1.07) for FRAP and 0.57 (95%CI, 0.36-0.90) for TRAP.

CONCLUSIONS

A diet rich in antioxidant capacity reduced gastric cancer risk, suggesting a high consumption of fruit and vegetables and a moderate consumption of wine and whole cereals.

Serum total antioxidant capacity in oral carcinoma patients

Context:

Oxidative stress is a major determinant in carcinogenesis and serum total antioxidant capacity (TAC) indirectly reflects the level of oxidative stress. Although oral cancer is the third most frequent cancer in Indian population, there are no standard noninvasive marker for early detection and monitoring therapeutic response in oral cancer patients.

Aims:

This study was carried out to investigate implications of serum TAC in oral cancer by evaluating pre- and post-operative levels in oral cancer patients.

Settings and Designs:

It was a prospective single blinded study.

Subjects and Methods:

Serum TAC was measured using ferric-reducing antioxidant power assay. Pre- and post-operative values were estimated and compared in 30 oral cancer patients who underwent surgery.

Statistical Analysis Used:

Paired t-test was used to compare pre- and post-operative values.

Results:

Compared to the normal value, both pre- and post-operative serum TAC were significantly low in oral cancer patients. However, there was no statistically significant difference between pre- and postoperative levels.

Conclusions:

In this study, low mean serum TAC was detected in oral cancer patients. However, its diagnostic and prognostic significance in oral cancer needs further investigation.

Inverse association between dietary habits with high total antioxidant capacity and prevalence of frailty among elderly Japanese women: a multicenter cross-sectional study

OBJECTIVE

To examine the association of dietary habits with high total antioxidant capacity (TAC) with frailty among elderly Japanese women.

DESIGN

Cross-sectional multicenter study.

SETTING

Thirty-five of 47 prefectures in Japan.

PARTICIPANTS

2121 grandmothers or acquaintances of dietetic students aged 65 and older.

MEASUREMENTS

Dietary TAC and food intakes were calculated using a validated brief-type self-administered diet history questionnaire. The TAC value of each food was assigned using four different assays, ferric reducing ability of plasma (FRAP), oxygen radical absorbance capacity (ORAC), Trolox equivalent antioxidant capacity (TEAC), and total radical-trapping antioxidant parameter (TRAP). Frailty was defined as the presence three or more of the following four components: slowness and weakness (two points), exhaustion, low physical activity, and unintentional weight loss.

RESULTS

The number of subjects with frailty was 486 (23%). Multivariate adjusted ORs (95% CI) for frailty in the highest compared to the lowest quintile were 0.35 (0.24, 0.53) for FRAP, 0.35 (0.23, 0.52) for ORAC, 0.40 (0.27, 0.60) for TEAC, and 0.41 (0.28, 0.62) for TRAP. The intakes of green tea, coffee, vegetables, and fruits which contribute to dietary TAC were also associated with lower odds of frailty (the range of multivariate adjusted OR: 0.47 for vegetables to 0.77 for green tea), although the odds ratios were less marked than those of dietary TAC.

CONCLUSIONS

Dietary habits with high TAC showed a stronger inverse association with frailty in elderly Japanese women than the individual foods examined.

Anticancer activities of citrus peel polymethoxyflavones related to angiogenesis and others

Citrus is a kind of common fruit and contains multiple beneficial nutrients for human beings. Flavonoids, as a class of plant secondary metabolites, exist in citrus fruits abundantly. Due to their broad range of pharmacological properties, citrus flavonoids have gained increased attention. Accumulative in vitro and in vivo studies indicate protective effects of polymethoxyflavones (PMFs) against the occurrence of cancer. PMFs inhibit carcinogenesis by mechanisms like blocking the metastasis cascade, inhibition of cancer cell mobility in circulatory systems, proapoptosis, and antiangiogenesis. This review systematically summarized anticarcinogenic effect of citrus flavonoids in cancer therapy, together with the underlying important molecular mechanisms, in purpose of further exploring more effective use of citrus peel flavonoids.

Impact of a complex nutraceutical supplement on primary tumour formation and metastasis in Trp53+/- cancer-prone mice

A complex dietary supplement designed to impact multiple mechanisms associated with aging and cancer reduced overall tumorigenesis in cancer-prone heterozygous Trp53+/- mice by ~30% (P < 0.018). Carcinomas were reduced by 67% (P < 0.006). Remarkably, metastasis (a leading cause of cancer mortality) was undetectable in treated animals (P < 0.004), and the occurrence of multiple primary tumours was reduced by 74% (P < 0.012). Reduction of pulmonary adenocarcinoma by 62% (P < 0.021) was of particular note given that lung cancer is the second leading cause of death in humans. Tumours showed pronounced age-related expression in untreated animals older than 600 days. Benefits of treatment only emerged in these later ages, suggesting that the supplement acted on mechanisms common to aging and cancer. The supplement was administered daily on bagel bits that were usually eaten within minutes by the mice. Although longevity was not statistically different between treatments, longevity was strongly related to the compliance of mice in eating the supplement. Linear regression revealed a strong positive relationship between the proportion of supplement eaten and the longevity of mice within the treatment group (P < 0.0001).